It is currently 24 Feb 2018, 09:36

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# Twenty-five adults reported the amount of time each spent st

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 43896

### Show Tags

08 May 2013, 06:02
2
KUDOS
Expert's post
Refer to the attached file.
Attachments

IR 4.docx [32.98 KiB]

_________________
Manager
Joined: 11 Jun 2010
Posts: 83
Re: Twenty-five adults reported the amount of time each spent st [#permalink]

### Show Tags

16 May 2013, 19:37
1
KUDOS
1
This post was
BOOKMARKED
1. To find the least possible mean the sum of all hours exercised must be the minimum.
For 0-1 hours lets assume all 5 exercised the minimum possible of just over 0 hours and same for all bars.
so SUM of hours exercised = 0*5 + 1*3+2*2+3*3+4*4+5*5+0+0+8*1+0+10*0 = 78
# respondents = 25
average = 78/25 = 3.12

2. # respondents who exercised on average <0.5 hours per day
If Avg hours exercised = 0.5 hours per day the Total hours exercised during the week will be 0.5*7 OR 3.5 hours/week
We need to count respondents who exercise below 3.5 hours per week.
That will include all in 0-1 hour, 1-2 hr, 2-3 hour and since 3.5 lies in between 3-4 band, we can take 2 cases:
CAse 1: where we assume all 4 in 3-4 years exercise MORE than 3.5 hours
Total # respondednts in that case = 5 + 3 + 2 + 4 = 14 (this is the maximum)
CAse 2: where we assume all 4 in 3-4 years exercise LESS than 3.5 hours
Total # respondednts in that case = 5 + 3 + 2 = 10 (this is the minimum)
Range od 10-14 respondents
Intern
Joined: 09 Nov 2013
Posts: 10
Re: Twenty-five adults reported the amount of time each spent st [#permalink]

### Show Tags

03 May 2014, 07:03
2
This post was
BOOKMARKED
srcc25anu wrote:
1. To find the least possible mean the sum of all hours exercised must be the minimum.
For 0-1 hours lets assume all 5 exercised the minimum possible of just over 0 hours and same for all bars.
so SUM of hours exercised = 0*5 + 1*3+2*2+3*3+4*4+5*5+0+0+8*1+0+10*0 = 78
# respondents = 25
average = 78/25 = 3.12

2. # respondents who exercised on average <0.5 hours per day
If Avg hours exercised = 0.5 hours per day the Total hours exercised during the week will be 0.5*7 OR 3.5 hours/week
We need to count respondents who exercise below 3.5 hours per week.
That will include all in 0-1 hour, 1-2 hr, 2-3 hour and since 3.5 lies in between 3-4 band, we can take 2 cases:
CAse 1: where we assume all 4 in 3-4 years exercise MORE than 3.5 hours
Total # respondednts in that case = 5 + 3 + 2 + 4 = 14 (this is the maximum)
CAse 2: where we assume all 4 in 3-4 years exercise LESS than 3.5 hours
Total # respondednts in that case = 5 + 3 + 2 = 10 (this is the minimum)
Range od 10-14 respondents

Thanks for the explanation! I fully understand the solution, but it took me almost 4 minutes to do it. Anyone know of a faster way to solve this question?

Thanks!
Intern
Joined: 20 May 2014
Posts: 37
Location: India
Schools: IIMC
GMAT 1: 700 Q51 V32
Re: Twenty-five adults reported the amount of time each spent st [#permalink]

### Show Tags

23 May 2014, 04:16
1
KUDOS
Hi Ashsim,

Part 1 Solution:

Sum of [Number of respondents * Least value of time spent in the range]
= 5*0 + 3*1 + 2*2 + 4*3 + 4*4 + 5*5 + 1*8 + 1*10
= 78

Average = $$\frac{78}{25} = 3.12$$

Part 2 Solution:

Less than 0.5 hr per day = less than 3.5 hr per week

Minimum number = 5 + 3 + 2 + 0 = 10 (When respondents spending time between 3 and 4 have values greater than 3.5)
Maximum Number = 5 + 3 + 2 + 4 = 14 (When respondents spending time between 3 and 4 have values less than 3.5)

I hope it could be solved in 2 mins

Rgds,
Rajat
_________________

If you liked the post, please press the'Kudos' button on the left

Manager
Joined: 28 Dec 2013
Posts: 72
Re: Twenty-five adults reported the amount of time each spent st [#permalink]

### Show Tags

06 Aug 2014, 11:01
rajatjain14 wrote:
Hi Ashsim,

Part 1 Solution:

Sum of [Number of respondents * Least value of time spent in the range]
= 5*0 + 3*1 + 2*2 + 4*3 + 4*4 + 5*5 + 1*8 + 1*10
= 78

Average = $$\frac{78}{25} = 3.12$$

Part 2 Solution:

Less than 0.5 hr per day = less than 3.5 hr per week

Minimum number = 5 + 3 + 2 + 0 = 10 (When respondents spending time between 3 and 4 have values greater than 3.5)
Maximum Number = 5 + 3 + 2 + 4 = 14 (When respondents spending time between 3 and 4 have values less than 3.5)

I hope it could be solved in 2 mins

Rgds,
Rajat

Question : How do we know that less than 0.5 hr per day = less than 3.5 hr per week?
Manager
Joined: 12 Nov 2016
Posts: 137
Concentration: Entrepreneurship, Finance
GMAT 1: 620 Q36 V39
GMAT 2: 650 Q47 V33
Re: Twenty-five adults reported the amount of time each spent st [#permalink]

### Show Tags

15 Nov 2017, 00:49
sagnik242 wrote:
rajatjain14 wrote:
Hi Ashsim,

Part 1 Solution:

Sum of [Number of respondents * Least value of time spent in the range]
= 5*0 + 3*1 + 2*2 + 4*3 + 4*4 + 5*5 + 1*8 + 1*10
= 78

Average = $$\frac{78}{25} = 3.12$$

Part 2 Solution:

Less than 0.5 hr per day = less than 3.5 hr per week

Minimum number = 5 + 3 + 2 + 0 = 10 (When respondents spending time between 3 and 4 have values greater than 3.5)
Maximum Number = 5 + 3 + 2 + 4 = 14 (When respondents spending time between 3 and 4 have values less than 3.5)

I hope it could be solved in 2 mins

Rgds,
Rajat

Question : How do we know that less than 0.5 hr per day = less than 3.5 hr per week?

assuming 7 day week (not weekend break ) 7*0.5 = 3.5
Manager
Joined: 17 Mar 2014
Posts: 160
Re: Twenty-five adults reported the amount of time each spent st [#permalink]

### Show Tags

01 Jan 2018, 18:04
Erjan_S wrote:
sagnik242 wrote:
rajatjain14 wrote:
Hi Ashsim,

Part 1 Solution:

Sum of [Number of respondents * Least value of time spent in the range]
= 5*0 + 3*1 + 2*2 + 4*3 + 4*4 + 5*5 + 1*8 + 1*10
= 78

Average = $$\frac{78}{25} = 3.12$$

Part 2 Solution:

Less than 0.5 hr per day = less than 3.5 hr per week

Minimum number = 5 + 3 + 2 + 0 = 10 (When respondents spending time between 3 and 4 have values greater than 3.5)
Maximum Number = 5 + 3 + 2 + 4 = 14 (When respondents spending time between 3 and 4 have values less than 3.5)

I hope it could be solved in 2 mins

Rgds,
Rajat

Question : How do we know that less than 0.5 hr per day = less than 3.5 hr per week?

assuming 7 day week (not weekend break ) 7*0.5 = 3.5

yeah I assumed weekend break and got this question wrong.
Re: Twenty-five adults reported the amount of time each spent st   [#permalink] 01 Jan 2018, 18:04
Display posts from previous: Sort by

# Twenty-five adults reported the amount of time each spent st

Moderators: chetan2u, Bunuel

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.